Harucom Board

Harucom Board is a board built around the RP2350A microcontroller, featuring DVI video output, USB host, stereo PWM audio, and expansion connectors.

Table of Contents

Specifications

Item Specification
MCU Raspberry Pi RP2350A (ARM Cortex-M33, dual-core)
Flash 16 MB QSPI (first 8 MB: firmware, last 8 MB: FAT filesystem)
PSRAM 8 MB QSPI (APS6404L, connected via QMI CS1)
Video Output DVI (via HSTX, Type-A 19-pin connector)
Audio Stereo PWM (3.5mm jack)
USB-C Power supply & data (device port)
USB-A Host port (PIO-USB)
Buttons 8 tactile buttons (ADC resistor ladder)
Expansion Grove x 2, SPI, SWD
LED Red (GPIO 1), Green (GPIO 23)

DVI Video Output

Uses HSTX (High-Speed Serial Transmit) to output DVI signals. Equipped with a Type-A 19-pin connector, allowing connection to a monitor via an HDMI cable.

Outputs 640x480 @ 60Hz video, supporting both text mode and graphics mode.

USB

USB-A (Host Port)

You can connect a keyboard directly to the USB-A port.

USB-C (Device Port)

Used for power supply and data communication. Connected to the RP2350’s native USB PHY, so it is also used for firmware updates.

Audio

Stereo PWM audio output. Equipped with a 3.5mm jack.

Buttons

Equipped with 8 tactile buttons. Uses a resistor ladder (voltage divider) scheme, with 4 buttons connected to each of 2 ADC channels.

Grove Connectors

Equipped with Grove connectors that can supply 5V power. You can connect various sensors and modules for I2C, UART, ADC, GPIO, and other purposes.

SPI Pin Header

Equipped with an SPI bus pin header. You can connect SPI devices such as SD card modules.

I2C Pin Header

Equipped with an I2C pin header that supplies 3.3V power. Convenient for connecting modules such as I2C displays.

Open-Source Hardware

Harucom Board is open-source hardware. The board design is published under the CERN-OHL-P v2 (Permissive) license, and anyone is free to use, modify, and redistribute it.